Pfizer and its German collaborator BioNTech on Friday submitted an application to the Food and Drug Administration for full approval of their COVID-19 vaccine. They announced that they will be submitting data to the FDA on a rolling basis over the coming weeks, with a request for priority review. It's not clear how long that review will take. Like other vaccines available in the U.S., Pfizer-BioNTech have been providing their vaccine under an "emergency use authorization," which allowed them to provide safety and effectiveness data after tracking trial participants for an average of two months instead of the usual six months.